A Schiff base group synthesized with 2-aldehydepyridine and 4-aminophenol was introduced into 2,2'-dioxybiphenyl cyclophosphazenes N₃P₃(O₂C₁₂H₈)₂Cl₂ (1) and N₃P₃(O₂C₁₂H₈)Cl₄ (2) by nucleophilic substitution. Two novel compounds used as multidentate ligands, N₃P₃(O₂C₁₂H₈)₂(p-O-Ph-N＝C-Py)₂ (3) and N₃P₃(O₂C₁₂H₈)(p-O-Ph-N＝C-Py)₄ (4), were obtained. Their structures were established by elemental analysis, IR, ¹H NMR, ³¹P NMR and TOFMS measurements. The absorption and emission spectra of the two ligands as well as the influences of adding H^＋ and Cu^＋ ions upon the spectra were investigated. The results indicated that the absorption and emission spectra of the two ligands are sensitive to H^＋ and Cu^＋ ions, which make them have an applied interest as fluorescent sensors for H^＋ and Cu^＋ ions.

Key words: cyclophosphazene, Schiff base, spectroscopy, fluorescent sensor